Offset boom for digging machines



July 17, 1956 D. F. PRZYBYLSKI OFFSET BOOM FOR DIGGING MACHINES 2 Sheets-Sheet 1 Filed Jan. 16, 1953 July 17, 1956 Filed Jan. 16, 1955 2 Sheets-Sheet 2 INVENTOR.

United States Patent OFFSET ROOM FOR DIGGING MACHINES Daniel F. Przybylski, Winona, Minn.

Application January 16, 1953, Serial No. 331,587

6 Claims. (Cl. 214-138) My present invention relates to improvements in digging or trenching machines.

An object of this invention is to provide a novel offset boom.

Another object is to provide a cam support for a hydraulic ram.

Still another object is to provide a novel digging dipper or bucket.

These and other objects will be apparent from the following description, reference being had to the drawings.

To the above end, generally stated, the invention consists of the novel devices and combination of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a side elevational view of the invention attached to a turn post on a trailer, fragmentarily shown, and also showing the invention in two different positions by means of broken lines;

Fig. 2 is a fragmentary side elevational view of the intermediate portion of the ofiset boom, and the outer end portion of the hydraulic ram for operating the boom, on an enlarged scale, with a portion of the supporting ram broken away;

Fig. 3 is a view of the digging dipper in longitudinal central section, and also showing in elevation fragments of the attached boom, dipper stick and hydraulic ram for operating the bucket;

Fig. 4 is a bottom plan view of the parts shown in Fig. 3;

Fig. 5 is a detail view principally in section taken on the irregular line 55 of Fig. l, on an enlarged scale; and

Fig. 6 is a detail view principally in section taken on the line 6--6 of Fig. 1, on an enlarged scale.

The numeral 7 indicates a fragment of a two-wheeled trailer having a sub-frame 8, a main upright frame 9 and a turn post 10. This turn post 10 is mounted on a step bearing 11 and turnable in a sleeve bearing 12, both of which are fixed to the main frame 9. An upper pair of upper laterally spaced ears 13 and a like pair of lower ears 14 are rigidly secured to the turn post 10. The turn post 10 is provided at its lower end portion with a large sheave 15 having a grooved periphery to receive a hydraulically operated cable, not shown, for turning the post 10.

Referring now in detail to the invention, the numeral 16 indicates a boom, the rear end portion of which extends between the lower pair of cars 14 and is pivoted thereto. This boom 16, at its rear end portion, is upwardly oifset at 17 for a highly important purpose, as will hereinafter appear. A hydraulic ram 18 overlying the boom 16 is provided for raising or lowering said boom. This ram 18 includes a cylinder 19 and a piston 20 having a piston rod 21. The cylinder 19, at its inner end portion, is connected to the ears 13 by a universal coupling 22. The

Patented July 17, 1%55 piston rod 21, at its outer end portion, extends between a pair of upstanding ears 23, fixed to the outer end portion of the boom 16, and is pivoted thereto.

The cylinder 19 is supported, at its outer end, by a pair of rollers 24 that travel in a pair of long opposing channel-like trackways 25 between which the cylinder 19 and the piston rod 21 extend, see Fig. 5. The rollers 24 are journaled on a pair of trunnions 26 on a fixed collar 27 on the outer end portion of the cylinder 19. The trackways 25 are on the opposing sides of a pair of upright horizontally elongated side plates 28 between which the boom 16 extends longitudinally below the trackways 25. See Figs. 1, 2 and 5. The side plates 28 are secured one on each side of the boom 16 by machine screws 29 which extend through holes in the side plates 28 and have threaded engagement with a horizontal row of tubular members 36 rigidly secured one row to each side of the boom 16, see Fig. 5. These rows of tubular members 30 act as spacers for the side plates 28.

A dipper 31 is attached to the boom 16 by a dipper stick 32. This dipper stick 32 has on its inner end portion a pair of laterally spaced ears 33 vertically disposed between which the boom 16, at its outer end, projects and is pivoted thereto. The dipper stick 31, at its outer end portion, extends between and is pivoted to a pair of large laterally spaced crank-acting ears 34 that project rearwardly from the back of the dipper 31 to which they are rigidly secured.

A hydraulic ram 35 connects the dipper stick to the boom 16 and underlies said boom. This ram 35 includes a cylinder 36 and a piston 37 having a piston rod 38. A universal coupling 39 connects the cylinder 36, at its outer end portion, to a pair of depending ears 40 integral with the boom at the outer end of its offset portion 17. The connection of the ram 35 to the boom 16 is highly important as it permits said ram to be positioned close to the under side of the boom 16 and positioned parallel thereto, see Fig. l. The piston rod 38, at its outer end portion, projects between and is pivoted to a pair of laterally spaced ears 41. These cars 41 are fixed to the dipper stick 32 on the same side as the ears 33' and at its outer end portion.

The dipper 31 is moved pivotally relative to the dipper stick 32 by a hydraulic ram 42. The ram 42 includes a cylinder 43 and a piston 44 having a piston rod 45 and said cylinder is pivoted to a pair of laterally spaced ears 46 fixed to the outer end of the dipper stick 32 and projects from the opposite side of said dipper stick from the ears 33. The piston rod 45 extends between the ears 34 below the pivotal connection of the dipper stick 32 and is pivoted in one of the pairs of aligned holes 47 circumferentially spaced relative to said pivotal connection of the dipper stick 32.

The cylinders 19, 36 and 43 are provided with fittings 47, 48 and 49, respectively, through which fluid under pressure is introduced into said cylinder for operating their pistons. Hose connection, not shown, will be attached to the fittings 47, 48 and 49 that lead from a source of fluid supply under pressure through hand-controlled valves. The boom 16, the dipper stick 32 and the rams 18, 35 and 42 are all in the same vertical plane.

The dipper 31 is reinforced at its back by a channel bar 50 which extends longitudinally of said dipper with its flange resting thereon and rigidly secured thereto, see Figs. 3 and 4. The rollers 24 and the trackways 25 intermediately support the ram 18 so that the cylinder 19 and the piston rod 21 are always in axial alignment, thus preventing strain and excessive wear. The rollers 24 and cam channels 25 also prevent the piston rod 45 from being bent by flexing. The dipper 34 is provided with side teeth 51.

By attaching the cylinder 36 to the boom 16, at its point of ofiset, the digging dipper may be brought out of ground, from its lower dotted line position to its full line position close enough to the trailer so that the cylinder 36 cannot come in contact with the ground, thereby eliminating the condition in which said cylinder would become bent or in an inoperative condition. By having the cylinder 36 mounted at the point of offset of the boom 16 also raises it to a higher level from the ground when digging at full depth capacity and also reinforces the boom 16 at this point.

While there are herein disclosed but a limited number of embodiments of the structure, process and product of the invention herein presented, it is possible to produce still other embodiments without departing from the inventive concept herein disclosed, and it is desired, therefore, that only such limitations be imposed on the appended claims as are stated herein, or required by the prior art.

What I claim is:

1. In an assembly of the class described, a turn post, a boom pivoted to the turn post for movement in a vertical plane, a hydraulic ram connecting the boom to the turn post for raising or lowering the boom, said ram comprising a cylinder and a piston having a piston rod, said cylinder being pivoted at its inner end to the turn post,

said piston rod at its outer end being pivoted to the outer end portion of the boom, a pair of horizontally elongated members fixed one to each side of the boom and having on their inner sides a pair of opposing trackways between which the cylinder projects, and a pair of rollers journaled on the cylinder and arranged to travel in the trackways.

2. In an assembly of the class described, a turn post, a boom pivoted to the turn post for movement in a vertical plane, a hydraulic ram connecting the boom to the turn post for raising or lowering the boom, said ram comprising a cylinder and a piston having a piston rod, said cylinder being pivoted at its inner end to the turn post, said piston rod at its outer end being pivoted to the outer end portion of the boom, a pair of horizontally elongated side plates secured one to each side of the boom and having on their inner sides a pair of opposing trackways between which the cylinder projects, and a pair of rollers journaled on the cylinder and arranged to run in the trackways.

3. In an assembly of the class described, a turn post, a boom pivoted to the turn post for movement in a vertical plane, a hydraulic ram connecting the boom to the turn post for raising or lowering the boom, said ram comprising a cylinder and a piston having a piston rod, said cylinder being pivoted at its inner end to the turn post, said piston rod at its outer end being pivoted to the outer end portion of the boom, said boom having on each side a horizontal row of tubular members, a pair of side plates, screws attaching the side plates to the tubular members, said tubular members acting as spacers for the side plates, said side plates having on their inner sides a pair of opposing trackways between which the cylinder projects, a pair of trunnions secured, one to each side of the cylinder, and rollers journaled on the trunnions and arranged to run in the trackways.

4. In an assembly of the class described, a support, a boom pivoted at its inner end to the support to swing in a vertical plane, a hydraulic ram extending longitudinally over the boom for raising or lowering the same, said boom including a cylinder and piston having a piston rod, said cylinder being pivoted at its inner end to the support and said piston rod being pivoted at its outer end to the outer end portion of the boom, at least one long trackway being mounted on the boom, said cylinder at its outer end having means mounted to travel in the trackway and hold the cylinder and piston rod in axial alignment during the raising or lowering of the boom.

5. The structure defined in claim 4 in which the means mounted in the trackway is constructed and arranged to move the cylinder at its free end in a vertical plane variable distances from the longitudinal axis of the boom.

6. In an assembly of the class described, a support, a boom pivoted at its inner end to the support to swing in a vertical plane, a hydraulic ram extending longitudinally over the boom for raising or lowering the same, said boom including a cylinder and a piston having a piston rod, said cylinder being pivoted at its inner end to the support and said piston rod being pivoted at its outer end to the outer end portion of the boom, a pair of side plates fixed to the boom, said side plates having a pair of opposing trackways, said cylinder having a pair of rollers journaled on its outer end portion and arranged to run in the trackways to hold the cylinder and piston rod axially aligned.

References Cited in the file of this patent UNITED STATES PATENTS D. 162,873 Pilch Apr. 10, 1951 1,623,194 Marshall Apr. 5, 1927 2,107,895 Lundstrom Feb. 8, 1938 2,284,661 Joy June 2, 1942 2,416,409 Schield Feb. 25, 1947 2,470,779 Lankovski et a1 May 24, 1949 OTHER REFERENCES Digging publication, published early 1951, Form SP 574, Rev. 55l, by Sherman Products, Inc., order pp. 1 and 7 of publication. 

